Session: MF-08-01/10-01 Development of Stress Intensity Factor Solutions (Joint with C&S) and Pipeline Integrity

Paper Number: 60755

Start Time: Wednesday, July 14, 2021, 09:00 AM

60755 - Evaluation of Normalization Method With Crack Mouth Opening Displacement for Developing J-R Curves 

Fracture mechanics-based engineering critical analysis (ECA) is an important approach to assess structural integrity of various pressure vessels and oil/gas pipelines. In which, fracture toughness and its effective measurement are essential to the ECA method. In standard fracture toughness test methods, such as ASMT E1820, the unloading compliance method or electric potential drop method is recommended for measuring the incremental crack growth and then to develop a fracture resistance curve for a single specimen test. In order to measure fracture resistance curves in corrosive and other harsh environments, ASTM E1820 also suggests a normalization method to estimate the incremental crack size during the stale crack tearing. The normalization method is a semi-analytic method developed in the 1990s based on the load separation method with use of the load-line displacement (LLD) for single edge notched bend (SENB) specimens or compact tension (CT) specimens. The normalization method has been extensively utilized to develop J-R curves using SENB and CT specimens in various loading and environmental conditions. Recently, the normalization method was employed to determine J-R curves for single edge notched tension (SENT) specimens with use of crack mouth opening displacement (CMOD) rather than LLD. This paper will review the historic background in developing the normalization method and evaluate its J-R curves determined using SENB specimens with LLD and CMOD.

Presenting Author: Xian-Kui Zhu Savannah River National Lab

Authors: